共沉法合成中溫型固態氧化物燃料電池La0.6Sr0.4Co0.2Fe0.8O3-δ - Sm0.2Ce0.8 O3-δ複合陰極

Co-precipitation Synthesis of La0.6Sr0.4Co0.2Fe0.8O3-δ - Sm0.2Ce0.8 O3-δfor IT-SOFC Composite Cathode

鍾維軒(Wei Xuan Zhong)

指導教授 ： 王玉瑞

國立臺北科技大學/工程學院/資源工程研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00641

摘要

本研究利用KOH與尿素當作沉澱劑，以SDC(smarium-doped ceria)材料取代YSZ(yttria stabilized zirconia)材料，利用共沉法製備La0.6Sr0.4Co0.2Fe0.8O3-δ - Ce0.8Sm0.2O3-δ混合導體陰極材料。探討LSCF與SDC之間不同的披覆形態對於性質之影響。結果顯示以KOH合成LSCF粉末經煆燒900oC / 2 h後粉末粒徑為300~400 nm，比表面積為4.51 m2/g；而以尿素合成之SDC粉末形貌為長板狀與菱形狀形貌，顆粒大小約為2~4 μm，比表面積為2.20 m2/g；KOH合成之SDC粉末粒徑為50~100 nm，比表面積為6.51 m2/g。
LSCF:SDC配比為50:50 wt%時，LSCF-SDC複合粉末經煆燒900oC / 2 h後皆可形成單相之結構，並且經過950oC、1000oC、1100oC燒結後不會產生二次相之反應，表示LSCF與SDC之間的匹配性良好。並且研究結果發現將LSCF披覆於SDC上所形成的複合陰極其電性為最佳，測得其導電度在650℃時為93 S/cm。而SDC披覆於LSCF上其電性大幅衰退，測得其導電度在650℃為0.2 S/cm。

關鍵字

固態氧化物燃料電池 ； LSCF-SDC ； 複合陰極 ； 共沉法

並列摘要

In the study, we use KOH and carbamide as deposit agent. By co-precipitation method, we replace YSZ for SDC material as cathode material La0.6Sr0.4Co0.2Fe0.8O3-δ - Ce0.8Sm0.2O3-δ for mixed-conducting, and further discuss the property differences by the effect of coating between LSCF and SDC. As the research turns out that the particle size is 300~400 nm after LSCF powder had synthesized by KOH by sintering at 900oC / 2 h, and BET is ~ 4.51 m2/g; whereas the rhombus and long plank shape of SDC powder are attributed to the synthesis of urea, and particle size is between 2~4 μm, BET is ~ 2.20 m2/g; the particle size of SDC powder synthesized by KOH is 50~100 nm, BET is 6.51 m2/g.
LSCF:SDC content are 50:50 wt%, monophase structure can be obtained by sintering of LSCF-SDC composite powder at 900oC / 2 h, and there is no second phase reaction after sintering at 950oC, 1000oC, 1100oC respectively, showing that matching capability between LSCF and SDC is excellent. The result indicates that electric property will be the best as composite cathode of LSCF deposited on SDC material, and conductivity at 650℃ is 93 S/cm; nonetheless, the SDC deposition on the LSCF material largely contributes to the recession of electric property, and the obtained conductivity is 0.159 S/cm.

並列關鍵字

SOFC ； LSCF-SDC ； composite cathode ； coprecipitation

參考文獻

[3] Huayang Zhu, Robert J. Kee, “Enhanced ceria – a low-temperature SOFC electrolyte”, Solid State lonics 52, p.173-182 (1992).

[4] V. Dusastre, J.A. Kilner, “Optimisation of composite cathodes for intermediate temperature SOFC applications”, Solid State Ionics 126, p.163–174 (1999).

[5] Shaorong Wang, Tohru Kato, Susumu Nagata, Takeo Honda, Toshimi Kaneko, Nobuharu Iwashita, Masayuki Dokiya, “Performance of a La0.6Sr0.4Co0.8Fe0.2O3–Ce0.8Gd0.2O1.9–Ag cathode for ceria electrolyte SOFCs”, Solid State Ionics 146, p.203–210 (2002)

[6] S.C. Singhal, “Advances in solid oxide fuel cell technology”, Japanese Journal of Applied Physics. Solid State Ionics 135, p.305–313 (2000).

[7] Y. Mishima, H. Mitsuyasu, M. Ohtaki, and K. Eguchi, “Solid Oxide Fuel Cell with Composite Electrolyte Consisting of Samaria-Doped Ceria and Yltria-Stabilized Zirconia”, Solid State Ionics.